1. Field of the Invention
The invention relates to jack assemblies and is directed more particularly to such assemblies adapted to support shelter structures.
2. Description of the Prior Art
In the U.S. Army there is currently used a Modular Extendable Rigid Wall Shelter (MERWS) jack assembly for supporting the MERWS. The jack assembly is of low profile when fully retracted, when the height of the assembly is about 8xc2xd-9 inches. The low profile is required for ease of packaging for shipment. The jack assembly, when fully extended, is of an overall length of about 32xc2xd-33 inches. The jack thus has a xe2x80x9cthrowxe2x80x9d of about two feet, which is needed to accommodate variations in terrain on which the MERWS is erected in the field.
The current MERWS jack consists of multiple telescopically mounted threaded pipe sections, and is relatively expensive to manufacture. The current MERWS jack has exhibited a tendency toward binding at threaded interfaces, leading to increased time to deploy and time required for maintenance.
Accordingly, there is a need for an improved MERWS jack assembly which is less expensive to manufacture, less likely to bind, and which provides reduced time required for deployment and maintenance.
An object of the invention is, therefore, to provide an improved jack assembly for use with modular shelters, the assembly being less expensive to manufacture, less likely to bind, and requiring less time for deployment and maintenance.
With the above and other objects in view, a feature of the present invention is the provision of a jack assembly for supporting a shelter structure. The assembly comprises a first tubular member fixed at a first end thereof to a plate, a nut disposed in the first tubular member and fixed to the plate, the plate defining a central hole aligned with a central hole in the nut, and a threaded shaft extending through the plate central hole and threadedly engaged with the nut, the shaft having thereon a flat sided base portion. A second tubular member is telescopically mounted on and moveable on the first tubular member to elongate the assembly, and a lock member is provided for locking the second tubular member to the first tubular member in a position in which the first and second tubular members overlap and the lock member is disposed in a region of the overlap.
In accordance with a further feature of the aforesaid invention, the threaded shaft extends through the nut, and the flat sided base portion of the threaded shaft is adapted for engagement with a wrench by which the shaft may be turned in the nut to selectively increase and decrease the length of the assembly.
In accordance with a still further feature of the aforesaid invention, an end of the threaded shaft within the first tubular member is provided with a wrench connector, such that a wrench extended through the second tubular member is enabled to engage the wrench connector and turn the threaded shaft in the nut to selectively increase and decrease the length of the assembly.
The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular device embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.